Plant growth promotion and nutrient mobilization by indigenous bacteria from soil under long term wheat and maize cultivation in district Bhimber

The aim of present study was to investigate the potential of indigenous plant growth promoting bacteria (PGPB) for enhancing the nutrient availability and plant growth. Field experiment was conducted and total three sampling sites [Bhimber (BH), Samahni (SA) and Barnala (BA)] were selected. Samples were collected from fallow fields under long term (about 70 years) cultivation of wheat (Triticum aestivum) and maize (Zea mays). Soil nutrients and physicochemical properties were determined and climatic data was obtained from the nearest metrological station. Total 26 different isolates were obtained from the soils, out of which 10 were from SA while 8 each from BH and BA soils. The highest amount of IAA (44.8 mu g/mL), siderophore production (12.83 mu g/mL), N-fixation (128.6 mu g/mL) and P-sol (40.01 mu g/mL) was recorded in SA as compared to BH and BA soils while Ksol (13.61 mu g/mL) and Znsol (28.2 mu g/mL) was highest in BA. Bacillus spp. showed maximum IAA production (52.01 mu g/mL), Ksol (19.1 mu g/mL) and ZnSol (34.64 mu g/mL). The maximum GA (1371 mu g/mL), siderophore production (17.22 mu g/mL) and Psol (62.64 mu g/mL) was observed by Pseudomonas spp. The production and solubilization of some important plant growth hormones and nutrients were highest in SA by Bacillus, Rhizobium, Pseudomonas, BH by Pseudomonas and BA by Bacillus. It was concluded that PGPB have potential to promote growth of plants and nutrient regulation.